Web to lead form not working properly

Web to lead form not working properly

Sometime around April 4, 2014 my web to lead form on my website stopped sending the automatic reply to my email when the form was submitted.  The leads are registering in ZOHO and the submitter is receiving the automatic reply which notifies them that we will contact them shortly.  Since we weren't notified that the form was submitted, we never contacted the lead. Obviously, this sucks for business.  Any insight on how to remedy this would be greatly appreciated.